Preparation method of explosives with differrnt densities and explosives with different density

ABSTRACT

Disclosed are explosives, especially a preparation method for explosives of different densities and explosives of different densities. The method adjusts physical density by adding granular form physical density adjusting agent with 0.5-5.0 mm grain diameter and 0.03-0.30 g/cm3 bulk density when preparing explosives. The method can adjust the explosive&#39;s density within a large range to produce the explosives with a wide range of detonation velocity to meet different needs for explosive velocity according to different lithology, and simultaneously meet needs for different explosives in the same blasthole.

The application claims priority of the following Chinese patent applications:

-   1. Chinese patent application No. 201210002199.2, filed with Chine     Patent Office on Jan. 5, 2012, entitled “Preparation Method of     Emulsion Explosives with Different Densities and Emulsion Explosives     with Different Densities”. -   2. Chinese patent application No. 201210002098.5, filed with Chine     Patent Office on Jan. 5, 2012, entitled “Preparation Method of     Ammonium Nitrate Fuel Oil Explosives with Different Densities and     Ammonium Nitrate Fuel Oil Explosives with Different Densities”.

FIELD OF THE INVENTION

The invention relates to explosives, in particular to a preparation method of explosives with different densities and explosives with different densities.

BACKGROUND OF THE INVENTION

Generally, traditional explosives have a relatively narrow density range. However, due to different rock properties, different rocks need different detonation velocities of the explosives. Generally, the higher the hardness of the rocks is, the higher the required detonation velocity of the explosives is; and the lower the hardness of the rocks is, the lower the required detonation velocity of the rocks is. The detonation velocity of the explosives also has a linear relation with the density in a certain range. As the explosives prepared by the common explosive preparation method have the relatively narrow density range, the large-range regulation cannot be performed according to lithological changes to meet the requirements of different lithologies for different detonation velocities. To meet the requirements of the different lithologies for explosive energy, Slag interval charging or air-deck charging needs to be adopted, so that the perforation cost is wasted and the working time is wasted; and furthermore, detonation energy acted on the rocks is non-uniform, so that the blasting effect is affected. Therefore, a method capable of preparing explosives with a better blasting effect and a large density range is needed.

SUMMARY OF THE INVENTION

The invention aims at overcoming the shortcomings of the prior art as stated above and providing a preparation method of explosives with different densities. A variety of explosives within a relatively wide density range can be prepared through the method. The technical solution disclosed by the invention is as follows:

According to the preparation method of explosives with different densities of the invention, a granular physical density adjusting agent with the particle size of 0.5-5.0 mm and the bulk density of 0.03-0.30 g/cm³ is added in the preparation process of the explosives to adjust the density, and the explosives are emulsion explosives, heavy emulsion explosives, porous granular ammonium nitrate fuel oil explosives or heavy ammonium nitrate fuel oil explosives.

Optionally, the physical density adjusting agent is a granular physical density adjusting agent with the p apr particle particlesize of 2-4 mm and the bulk density of 0.07-0.20 g/cm³.

Optionally, the physical density adjusting agent is a physical density adjusting agent with adsorbability on diesel or without adsorbability on diesel; and the physical density adjusting agent with adsorbability on diesel is expanded perlite particles and/or dried broken plant particles, and the physical density adjusting agent without adsorbability on diesel is thermoplastic polymer foam particles.

Optionally, the thermoplastic polymer foam particles are one or a mixture of more than two of foam particles of polystyrene, polyethylene and polypropylene.

Optionally, the explosives are the emulsion explosives, and the preparation method comprises the following steps:

-   (101) injecting a sensitizing solution into an emulsion base to     prepare a mixture I, wherein the weight ratio of the emulsion base     to the sensitizing solution is (98-102):(1.0-3.2); and -   (102) adding the physical density adjusting agent into the mixture     I, and uniformly mixing and sensitizing to obtain the explosives; -   wherein the amount of the physical density adjusting agent is     0.1-35% of the weight of the emulsion base.

Optionally, the emulsion explosives are the heavy emulsion explosives, and the preparation method comprises the following steps:

-   (201) injecting a sensitizing solution into an emulsion base to     prepare a mixture I, wherein the weight ratio of the emulsion base     to the sensitizing solution is (98-102):(1.0-3.2); -   (202) uniformly mixing porous granular ammonium nitrate with the     diesel to prepare a mixture II, uniformly mixing the mixture I with     the mixture II to prepare a mixture III, wherein the content by     weight of the emulsion base in the mixture III is above 50%, and the     weight ratio of the porous granular ammonium nitrate to the diesel     is (93.5-95.5):(4.5-6.5); and -   (203) adding the physical density adjusting agent into the mixture     III, and uniformly mixing and sensitizing to obtain the explosives,     wherein the content by weight of the physical density adjusting     agent is 0.1-35% that of the mixture III by weight.

Optionally, the emulsion explosives are the heavy emulsion explosives, and the preparation method comprises the following steps:

-   (301) injecting a sensitizing solution into an emulsion base with     negative oxygen balance to prepare a mixture I, wherein the weight     ratio of the emulsion base to the sensitizing solution is     (98-102):(1.0-3.2); -   (302) uniformly mixing the mixture I with porous granular ammonium     nitrate to prepare a mixture IV; and -   (303) adding the physical density adjusting agent into the mixture     IV, and uniformly mixing and sensitizing to obtain the explosives; -   wherein the content by weight of the emulsion base in the mixture IV     is above 50%, and the content by weight of the physical density     adjusting agent in the mixture IV is 0.1-35%.

Optionally, the porous granular ammonium nitrate in the mixture II or the mixture IV is 10%, 30% or 45%.

Optionally, the explosives are the porous granular ammonium nitrate fuel oil explosives, the physical density adjusting agent is one or a mixture of more of physical density adjusting agents with adsorbability on diesel, and the preparation method of explosives with different densities comprises the following steps:

-   (101) uniformly mixing 93.5-95.5 parts by weight of porous granular     ammonium nitrate and 4.5-6.5 parts by weight of diesel to obtain a     mixture I; and -   (102) uniformly mixing the mixture I with the physical density     adjusting agent to obtain the porous granular ammonium nitrate fuel     oil explosives with the different densities; -   wherein the amount of the physical density adjusting agent is     0.1-35% of the total weight of the porous granular ammonium nitrate     and the diesel.

Optionally, the ammonium nitrate fuel oil explosives are the porous granular ammonium nitrate fuel oil explosives, the physical density adjusting agent is the physical density adjusting agent without adsorbability on diesel, and the preparation method comprises the following step: uniformly mixing 93.5-95.5 parts by weight of porous granular ammonium nitrate, 4.5-6.5 parts by weight of diesel and the physical density adjusting agent, wherein the weight of the physical density adjusting agent accounts for 0.1-35% of the total weight of the porous granular ammonium nitrate and the diesel.

Optionally, the ammonium nitrate fuel oil explosives are the heavy ammonium nitrate fuel oil explosives, and the preparation method comprises the following steps:

-   (201) uniformly mixing porous granular ammonium nitrate, the diesel     and the physical density adjusting agent to obtain a mixture II,     wherein the physical density adjusting agent is the physical density     adjusting agent without adsorbability on diesel, and the weight     ratio of the porous granular ammonium nitrate to the diesel is     (93.5-95.5):(4.5-6.5); -   (202) uniformly mixing an emulsion base with a sensitizing solution     to obtain a mixture III, wherein the weight ratio of the emulsion     base to the sensitizing solution is 100: (1.0-3.2); and -   (203) uniformly mixing the mixture II and the mixture III to prepare     the heavy ammonium nitrate fuel oil explosives, wherein the weight     ratio of the mixture II to the mixture III is not less than 1:1;     -   wherein the amount of the physical density adjusting agent is         0.1-35% of the total weight of the porous granular ammonium         nitrate, the diesel and the emulsion base.

Optionally, the ammonium nitrate fuel oil explosives are the heavy ammonium nitrate fuel oil explosives, and the preparation method comprises the following steps:

-   (301) uniformly mixing porous granular ammonium nitrate with the     diesel to obtain a mixture IV, wherein the weight ratio of the     porous granular ammonium nitrate to the diesel is     (93.5-95.5):(4.5-6.5); -   (302) uniformly mixing an emulsion base with a sensitizing solution     to obtain a mixture III, wherein the weight ratio of the emulsion     base to the sensitizing solution is 100: (1.0-3.2); and -   (303) uniformly mixing the mixture IV, the mixture III and the     physical density adjusting agent to prepare the heavy ammonium     nitrate fuel oil explosives, wherein the weight ratio of the mixture     IV to the mixture III is not less than 1:1, and the amount of the     physical density adjusting agent is 0.1-35% of the total weight of     the porous granular ammonium nitrate, the diesel and the emulsion     base.

Optionally, the ammonium nitrate fuel oil explosives are the heavy ammonium nitrate fuel oil explosives, and the preparation method comprises the following steps:

-   (401) uniformly mixing porous granular ammonium nitrate and an     emulsion base with negative oxygen balance to obtain a mixture V,     wherein the weight ratio of the porous granular ammonium nitrate to     the emulsion base is not less than 1:1; and -   (402) uniformly mixing the mixture V, a sensitizing solution and the     physical density adjusting agent and sensitizing at the temperature     of 0-90° C. for 15-20 min to prepare the heavy ammonium nitrate fuel     oil explosives; -   wherein the weight ratio of the emulsion base to the sensitizing     solution is 100:(1.0-3.2), and the amount of the physical density     adjusting agent is 0.1-35% of the total weight of the porous     granular ammonium nitrate and the emulsion base.

The invention further relates to explosives with different densities obtained through the above methods. When the content of the emulsion base in the emulsion explosives accounts for above 50% of the explosives, the emulsion explosives are the heavy emulsion explosives. The ammonium nitrate fuel oil explosives are divided into two major categories, one category is the porous granular ammonium nitrate fuel oil explosives and the other category is the heavy ammonium nitrate fuel oil explosives.

The invention has the following beneficial effects:

-   (1) The emulsion explosives with the density range of 0.3-1.25 g/cm³     and the detonation range of 1800-5500 m/s can be prepared through     the preparation method of the invention, and the requirements of     different lithologies for different detonation velocities of the     explosives can be met. -   (2) The explosives prepared through the method for preparing the     emulsion explosives of the invention have certain water resistance     and moisture resistance. -   (3) Compared with the way of adopting slag interval charging or     air-deck charging to adjust the detonation velocity of the ammonium     nitrate fuel oil explosives to adapt to the requirements of     different lithologies for different detonation velocities, the unit     consumption is saved, the detonation energy acted on rocks is     uniform, the blasting effect is good, the construction efficiency is     high, the backfill workload is small, surface masses are few, and     blasting toe rocks are few. -   (4) A variety of porous granular ammonium nitrate fuel oil     explosives which have the density of 0.3-0.95 g/cm³ and further     obtain the detonation velocity of 1600-3600 m/s and a variety of     heavy ammonium nitrate fuel oil explosives which have the density of     0.3-1.25 g/cm³ and further obtain the detonation velocity of     1800-5000 m/s can be prepared through the preparation methods of the     explosives of the invention, the requirements of different     lithologies of the explosives for different detonation velocities     can be met, and the requirements of different explosives in a same     blast hole can be met. -   (5) By adopting the ammonium nitrate fuel oil explosives of the     invention, the explosives with different densities, different     detonation velocities and different varieties can be loaded into the     same blast hole, slag interval charging or air-deck charging is not     required in the process, the backfill height can be reduced to 20-23     times, and the backfill height is the most reasonable backfill     height; and compared with the backfill height for the aperture     length of 30-33 times in the prior art, the backfill height not only     ensures the effects, but also reduces the surface masses. -   (6) Compared with a laboratory, the invention can realize     large-scale production, be implemented by a multifunctional site     mixing and loading vehicle and decide the density of the ammonium     nitrate fuel oil explosives, the heavy ammonium nitrate fuel oil     explosives, the emulsion explosives and the heavy emulsion     explosives by regulating the output of the physical density     adjusting agent through a helix material conveying machine.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The invention is described in detail in combination with the following specific embodiments, but the invention is not limited to the listed embodiments.

Embodiment 1

Explosives are prepared by taking 9.8 kg of an emulsion base, injecting 0.32 kg of a sensitizing solution, then adding 3.43 kg of polystyrene foam particles with the average particle size of 2 mm and the bulk density of 0.07 g/cm³ and uniformly mixing. The density is determined to be 0.30 g/cm³, and the detonation velocity is tested to be 1502 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 2

Explosives are prepared by taking 10 kg of an emulsion base, injecting 0.1 kg of a sensitizing solution, uniformly mixing, adding 0.01 kg of expanded perlite particles with the average particle size of 5 mm and the bulk density of 0.3 g/cm³ and uniformly mixing. The density is determined to be 1.25 g/cm³, and the detonation velocity is tested to be 4993 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T 13228-1991.

Embodiment 3

Explosives are prepared by taking 10.2 kg of an emulsion base, injecting 0.3 kg of a sensitizing solution, adding 1 kg of rice husks with the average particle size of 3 mm and the bulk density of 0.1 g/cm³ and uniformly mixing. The density is determined to be 0.53 g/cm³, and the detonation velocity is tested to be 2702 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 4

Explosives are prepared by the following steps: (1) taking 10 kg of an emulsion base, and injecting 0.1 kg of a sensitizing solution and uniformly mixing; then (2) taking 4.5 kg of porous granular ammonium nitrate and 0.26 kg of diesel, and uniformly mixing; (3) uniformly mixing mixtures prepared by the step (1) and the step (2); and (4) adding 0.0145 kg of polypropylene foam particles with the average particle size of 2.5 mm and the bulk density of 0.08 g/cm³ into the mixture prepared in the step (3), and uniformly mixing. The density is determined to be 1.25 g/cm³, and the detonation velocity is tested to be 5003 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 5

Explosives are prepared by the following steps: (1) taking 9.8 kg of an emulsion base, and injecting 0.32 kg of a sensitizing solution and uniformly mixing; (2) taking 1 kg of porous granular ammonium nitrate and 0.058 kg of diesel, and uniformly mixing; (3) uniformly mixing mixtures prepared by the step (1) and the step (2); and (4) adding 3.78 kg of a mixture of polystyrene foam particles with the average particle size of 2 mm and the bulk density of 0.1 g/cm³ and expanded perlite particles (wherein the mixture contains 1 kg of polystyrene foam particles and 2.78 kg of expanded perlite particles) into the mixture prepared in the step (3), and uniformly mixing. The density is determined to be 0.3 g/cm³, and the detonation velocity is tested to be 1508 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 6

Explosives are prepared by the following steps: (1) taking 10.2 kg of an emulsion base, and injecting 0.3 kg of a sensitizing solution and uniformly mixing; (2) taking 3 kg of porous granular ammonium nitrate and 0.174 kg of diesel, and uniformly mixing; (3) uniformly mixing mixtures prepared by the step (1) and the step (2); and (4) adding 2 kg of expanded perlite particles with the particle size of 5.0 mm and the bulk density of 0.3 g/cm³ into the mixture prepared in the step (3), and uniformly mixing. The density is determined to be 0.73 g/cm³, and the detonation velocity is tested to be 3402 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 7

Explosives are prepared by taking 10 kg of an emulsion base with negative oxygen balance, injecting 0.1 kg of a sensitizing solution and uniformly mixing; then adding 4.5 kg of porous granular ammonium nitrate, uniformly mixing, finally adding 5 kg of polyethylene foam particles with the average particle size of 4.5 mm and the bulk density of 0.25 g/cm³, uniformly mixing and sensitizing. The density is determined to be 0.52g/cm³, and the detonation velocity is tested to be 2613 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 8

Explosives are prepared by taking 9.8 kg of an emulsion base with negative oxygen balance, injecting 0.20 kg of a sensitizing solution and uniformly mixing; then adding 1 kg of porous granular ammonium nitrate, and uniformly mixing; finally adding 1.5 kg of a mixture of polypropylene, polystyrene and polyethylene foam particles with the average particle size of 4 mm and the bulk density of 0.20 g/cm³ (wherein the mixture contains 0.5 kg of polypropylene, 0.5 kg of polystyrene and 0.5 kg of polyethylene), uniformly mixing and sensitizing. The density is determined to be 0.68 g/cm³, and the detonation velocity is tested to be 2946 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 9

Explosives are prepared by taking 10.2 kg of an emulsion base with negative oxygen balance, injecting 0.32 kg of a sensitizing solution and uniformly mixing; then adding 3 kg of porous granular ammonium nitrate, and uniformly mixing; and finally adding 0.01 kg of expanded perlite particles with the average particle size of 0.5 mm and the bulk density of 0.03 g/cm³, uniformly mixing and sensitizing. The density is determined to be 1.20 g/cm³, and the detonation velocity is tested to be 4308 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

The emulsion base with the negative oxygen balance in embodiments 4-6 is prepared by adopting the following method: uniformly mixing 85 kg of ammonium nitrate, 0.122 kg of thiourea and 14.1 kg of water at the temperature of 80° C., and regulating the pH value to 3.5 by using sodium hydroxide and acetic acid, wherein the crystallization point is 70° C., and the turbidity of a solution is 0.8 NTU, as measured; adding a diatomite adsorbent into the solution, and performing suction filtration by a coarse filter and a fine filter for 30 min in total to obtain a pure oxidizer salt water solution for later use; melting and uniformly mixing 1.8 kg of LZ2820 polyisobutylene succinic anhydride emulsifier and 5 kg of paraffin oil at the temperature of 70° C. to prepare an oil phase for later use; and emulsifying the obtained oxidizer salt water solution and the oil phase in an emulsifier at the temperature of 80° C. to form a water-in-oil type emulsion explosive base. The viscosity is determined to be 15 BU.

The emulsion base in embodiments 1-3 and 7-9 is prepared by adopting the following method: uniformly mixing 79.9 kg of ammonium nitrate, 0.122 kg of thiourea and 14.1 kg of water at the temperature of 80° C., and regulating the pH value to 3.5 by using sodium hydroxide and acetic acid, wherein the crystallization point is determined to be 70° C., and the turbidity of a solution is 0.8 NTU; adding a diatomite adsorbent into the solution, and performing suction filtration by a coarse filter and a fine filter for 30 min in total to obtain a pure oxidizer salt water solution for later use;

melting and uniformly mixing 1.8 kg of LZ2820 polyisobutylene succinic anhydride emulsifier and 6.22 kg of paraffin oil at the temperature of 70° C. to prepare an oil phase for later use; and emulsifying the obtained oxidizer salt water solution and the oil phase in an emulsifier at the temperature of 80° C. to form a water-in-oil type emulsion explosive base. The viscosity is determined to be 15 BU.

The sensitizing solution in embodiments 4-9 is prepared by adopting the following method: preparing the sensitizing solution by 0.09 kg of sodium nitrite, 0.09 kg of sodium bicarbonate and 2.62 kg of water.

The invention further relates to the emulsion explosives with the different densities and the heavy emulsion explosives with the different densities, prepared by the methods described in the above embodiments.

Embodiment 10 Preparation of Porous Granular Ammonium Nitrate Fuel Oil Explosives

Porous granular ammonium nitrate fuel oil explosives are prepared by taking 9.35 kg of porous granular ammonium nitrate and 0.65 kg of diesel, uniformly mixing, then adding 0.01 kg of expanded perlite particles with the particle size of 0.5 mm and the bulk density of 0.03 g/cm³ into a mixture of the porous granular ammonium nitrate and the diesel, and uniformly mixing. The density is determined to be 0.9 g/cm³, and the detonation velocity of the explosives in the embodiment is tested to be 3302 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 11 Preparation of Porous Granular Ammonium Nitrate Fuel Oil Explosives

Porous granular ammonium nitrate fuel oil explosives are prepared by taking 9.55 kg of porous granular ammonium nitrate, 0.45 kg of diesel and 3.5 kg of polystyrene foam particles with the particle size of 2.3 mm and the bulk density of 0.12 g/cm³. The density is determined to be 0.30 g/cm³, and the detonation velocity of the explosives in the embodiment is tested to be 1633 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 12 Preparation of Porous Granular Ammonium Nitrate Fuel Oil Explosives

Porous granular ammonium nitrate fuel oil explosives are prepared by taking 9.45 kg of porous granular ammonium nitrate and 0.55 kg of diesel, uniformly mixing, then adding 1.5 kg of rice husks with the particle size of 5 mm and the bulk density of 0.3 g/cm³ into a mixture of the porous granular ammonium nitrate and the diesel, and uniformly mixing. The density is determined to be 0.71 g/cm³, and the detonation velocity of the explosives in the embodiment is tested to be 3306 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 13 Preparation of Heavy Ammonium Nitrate Fuel Oil Explosives

Heavy ammonium nitrate fuel oil explosives of the embodiment are prepared by the following steps: (al) taking 9.55 kg of porous granular ammonium nitrate, 0.45 kg of diesel and 0.0109 kg of polyethylene foam particles with the particle size of 5 mm and the bulk density of 0.3/cm³ and uniformly mixing; (b1) uniformly mixing 4.8 kg of emulsion base and 0.15 kg of sensitizing solution; and (c1) uniformly mixing mixtures obtained in the step (a1) and the step (b1), then loading into a blast hole and sensitizing at the temperature of 0° C. for 20 min. The density is determined to be 1.25 g/cm³, and the detonation velocity is tested to be 4489 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 14 Preparation of Heavy Ammonium Nitrate Fuel Oil Explosives

Heavy ammonium nitrate fuel oil explosives of the embodiment are prepared by the following steps: (a3) taking 9.45 kg of porous granular ammonium nitrate, 0.55 kg of diesel and 1.95 kg of polypropylene foam particles with the particle size of 3 mm and the bulk density of 0.12/ cm³ and uniformly mixing; (b3) uniformly mixing 3 kg of emulsion base and 0.084 kg of sensitizing solution; and (c3) uniformly mixing mixtures obtained in the step (a3) and the step (b3).

The density is determined to be 0.5 g/cm³, and the detonation velocity is tested to be 2608 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 15 Preparation of Heavy Ammonium Nitrate Fuel Oil Explosives

Heavy ammonium nitrate fuel oil explosives of the embodiment are prepared by the following steps: (a4) taking 9.45 kg of porous granular ammonium nitrate and 0.55 kg of diesel and uniformly mixing; (b4) uniformly mixing 4.8 kg of emulsion base and 0.048 kg of sensitizing solution; and (c4) uniformly mixing mixtures prepared in the step (a4) and the step (b4) and 5.25 kg of expanded perlite particles with the particle size of 2.5 mm and the bulk density of 0.10 g/cm³.

The density is determined to be 0.3 g/cm³, and the detonation velocity is tested to be 1633 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

Embodiment 16 Preparation of Heavy Ammonium Nitrate Fuel Oil Explosives

Heavy ammonium nitrate fuel oil explosives of the embodiment are prepared by the following steps: (a5) taking 9.35 kg of porous granular ammonium nitrate and 4 kg of emulsion base with negative oxygen balance, and uniformly mixing; (b5) adding 0.075 kg of sensitizing solution and 4.67 kg of foam particles of a polypropylene-polystyrene-polyethylene mixture (the mixture contains 1.5 kg of polypropylene, 1.67 kg of polystyrene and 1.5 kg of polyethylene) with the particle size of 3 mm and the bulk density of 0.12/cm³ into a mixture obtained in the step (a5) and uniformly mixing.

The density is determined to be 0.35 g/cm³, and the detonation velocity is tested to be 1805 m/s according to a method for measuring a detonation velocity of an industrial explosive of GB/T13228-1991.

The emulsion base with the negative oxygen balance in the embodiment is prepared by adopting the following method: uniformly mixing 79.9 kg of ammonium nitrate, 0.122 kg of thiourea and 14.1 kg of water at the temperature of 80° C., and regulating the pH value to 3.5 by using sodium hydroxide and acetic acid, wherein the crystallization point is determined to be 70° C., and the turbidity of a solution is 0.8 NTU; adding a diatomite adsorbent into the solution, and performing suction filtration by a coarse filter and a fine filter for 30 min in total to obtain a pure oxidizer salt water solution for later use; melting and uniformly mixing 1.8 kg of LZ2820 polyisobutylene succinic anhydride emulsifier and 6.22 kg of paraffin oil at the temperature of 70° C. to prepare an oil phase for later use; and emulsifying the obtained oxidizer salt water solution and the oil phase in an emulsifier at the temperature of 80° C. to form a water-in-oil type emulsion explosive base. The viscosity is determined to be 15 BU.

The negative oxygen balance in the embodiment means that oxygen contained in the emulsion base is insufficient to completely oxidize combustible elements.

The emulsion base in embodiments 13-15 is prepared by adopting the following method: uniformly mixing 85 kg of ammonium nitrate, 0.122 kg of thiourea and 14.1 kg of water at the temperature of 80° C., and regulating the pH value to 3.5 by using sodium hydroxide and acetic acid, wherein the crystallization point is determined to be 70° C., and the turbidity of a solution is 0.79 NTU; adding a diatomite adsorbent into the solution, and performing suction filtration by a coarse filter and a fine filter for 30 min in total to become a pure oxidizer salt water solution for later use; melting and uniformly mixing 1.8 kg of LZ2820 polyisobutylene succinic anhydride emulsifier and 5 kg of paraffin oil at the temperature of 70° C. to prepare an oil phase for later use; and emulsifying the obtained oxidizer salt water solution and the oil phase in an emulsifier at the temperature of 80° C. to form a water-in-oil type emulsion explosive base. The viscosity is determined to be 16 BU. The sensitizing solution in embodiments 4-7 is prepared by adopting the following method: preparing 0.09 kg of sodium nitrite, 0.09 kg of sodium bicarbonate and 2.62 kg of water into the sensitizing solution.

The invention further relates to the porous granular ammonium nitrate fuel oil explosives and the heavy ammonium nitrate fuel oil explosives with the different densities, prepared by the above embodiments. 

1-14. (canceled)
 15. A preparation method of explosives with different densities, characterized in that a granular physical density adjusting agent with the particle size of 0.5-5.0 mm and the bulk density of 0.03-0.30 g/cm³ is added in the preparation process of the explosives, and the explosives are emulsion explosives or ammonium nitrate fuel oil explosives.
 16. The preparation method of explosives with different densities according to claim 15, characterized in that the physical density adjusting agent is a granular physical density adjusting agent with the particle size of 2-4 mm and the bulk density of 0.07-0.20 g/cm³.
 17. The preparation method of explosives with different densities according to claim 15, characterized in that the physical density adjusting agent is a physical density adjusting agent with adsorbability on diesel or without adsorbability on diesel; and the physical density adjusting agent with adsorbability on diesel is of expanded perlite particles and/or dried broken plant particles, and the physical density adjusting agent without adsorbability on diesel is of thermoplastic polymer foam particles.
 18. The preparation method of explosives with different densities according to claim 17, characterized in that the thermoplastic polymer foam particles are of one or a mixture of more than two of foam particles of polystyrene, polyethylene and polypropylene.
 19. The preparation method of explosives with different densities according to claim 15, characterized in that when the explosives are emulsion explosives, the preparation method of explosives with different densities comprises the following steps: (101) injecting a sensitizing solution into an emulsion base to prepare a mixture I, wherein the weight ratio of the emulsion base to the sensitizing solution is (98-102):(1.0-3.2); and (102) adding the physical density adjusting agent into the mixture I, and uniformly mixing and sensitizing to obtain the explosives; wherein the amount of the physical density adjusting agent is 0.1-35% of the weight of the emulsion base.
 20. The preparation method of explosives with different densities according to claim 15, characterized in that when the explosives are heavy emulsion explosives in the emulsion explosives, the preparation method of explosives with different densities comprises the following steps: (201) injecting a sensitizing solution into an emulsion base to prepare a mixture I, wherein the weight ratio of the emulsion base to the sensitizing solution is (98-102):(1.0-3.2); and (202) uniformly mixing porous granular ammonium nitrate with the diesel to prepare a mixture II, and uniformly mixing the mixture I with the mixture II to prepare a mixture III, wherein the content by weight of the emulsion base in the mixture III is above 50%, and the weight ratio of the porous granular ammonium nitrate to the diesel is (93.5-95.5):(4.5-6.5); and (203) adding the physical density adjusting agent into the mixture III, and uniformly mixing and sensitizing to obtain the explosives, wherein the content by weight of the physical density adjusting agent is 0.1-35% that of the mixture III by weight.
 21. The preparation method of explosives with different densities according to claim 15, characterized in that when the explosives are heavy emulsion explosives in the emulsion explosives, the preparation method of explosives with different densities comprises the following steps: (301) injecting a sensitizing solution into an emulsion base with negative oxygen balance to prepare a mixture I, wherein the weight ratio of the emulsion base to the sensitizing solution is (98-102):(1.0-3.2); (302) uniformly mixing the mixture I with porous granular ammonium nitrate to prepare a mixture IV; and (303) adding the physical density adjusting agent into the mixture IV, and uniformly mixing and sensitizing to obtain the explosives, wherein the content by weight of the emulsion base in the mixture IV is above 50%, and the content by weight of the physical density adjusting agent in the mixture IV is 0.1-35%.
 22. The preparation method of explosives with different densities according to claim 20, characterized in that the content by weight of the porous granular ammonium nitrate in the mixture II or the mixture IV is 10%, 30% or 45%.
 23. The preparation method of explosives with different densities according to claim 17, characterized in that when the explosives are porous granular ammonium nitrate fuel oil explosives in the ammonium nitrate fuel oil explosives, the physical density adjusting agent is one or a mixture of more of physical density adjusting agents with adsorbability on diesel, and the preparation method of explosives with different densities comprises the following steps: (101) uniformly mixing 93.5-95.5 parts by weight of porous granular ammonium nitrate and 4.5-6.5 parts by weight of diesel to obtain a mixture I; and (102) uniformly mixing the mixture I with the physical density adjusting agent to obtain the porous granular ammonium nitrate fuel oil explosives with the different densities; wherein the amount of the physical density adjusting agent is 0.1-35% of the total weight of the porous granular ammonium nitrate and the diesel.
 24. The preparation method of explosives with different densities according to claim 16, characterized in that when the explosives are porous granular ammonium nitrate fuel oil explosives in the ammonium nitrate fuel oil explosives, the physical density adjusting agent is the physical density adjusting agent without adsorbability on diesel, and the preparation method of explosives with different densities comprises the following step: uniformly mixing 93.5-95.5 parts by weight of porous granular ammonium nitrate, 4.5-6.5 parts by weight of diesel and the physical density adjusting agent, wherein the weight of the physical density adjusting agent accounts for 0.1-35% of the total weight of the porous granular ammonium nitrate and the diesel.
 25. The preparation method of explosives with different densities according to claim 16, characterized in that when the explosives are heavy ammonium nitrate fuel oil explosives in the ammonium nitrate fuel oil explosives, and the preparation method of explosives with different densities comprises the following steps: (201) uniformly mixing porous granular ammonium nitrate, the diesel and the physical density adjusting agent to obtain a mixture II, wherein the physical density adjusting agent is the physical density adjusting agent without adsorbability on diesel, and the weight ratio of the porous granular ammonium nitrate to the diesel is (93.5-95.5):(4.5-6.5); (202) uniformly mixing an emulsion base with a sensitizing solution to obtain a mixture III, wherein the weight ratio of the emulsion base to the sensitizing solution is 100:(1.0-3.2); and (203) uniformly mixing the mixture II and the mixture III to prepare the heavy ammonium nitrate fuel oil explosives, wherein the weight ratio of the mixture II to the mixture III is not less than 1:1; wherein the amount of the physical density adjusting agent is 0.1-35% of the total weight of the porous granular ammonium nitrate, the diesel and the emulsion base.
 26. The preparation method of explosives with different densities according to claim 16, characterized in that when the explosives are heavy ammonium nitrate fuel oil explosives in the ammonium nitrate fuel oil explosives, the preparation method of explosives with different densities comprises the following steps: (301) uniformly mixing porous granular ammonium nitrate with the diesel to obtain a mixture IV, wherein the weight ratio of the porous granular ammonium nitrate to the diesel is (93.5-95.5):(4.5-6.5); (302) uniformly mixing an emulsion base with a sensitizing solution to obtain a mixture III, wherein the weight ratio of the emulsion base to the sensitizing solution is 100:(1.0-3.2); and (303) uniformly mixing the mixture IV, the mixture III and the physical density adjusting agent to prepare the heavy ammonium nitrate fuel oil explosives, wherein the weight ratio of the mixture IV to the mixture III is not less than 1:1, and the amount of the physical density adjusting agent is 0.1-35% of the total weight of the porous granular ammonium nitrate, the diesel and the emulsion base.
 27. The preparation method of explosives with different densities according to claim 16, characterized in that when the explosives are heavy ammonium nitrate fuel oil explosives in the ammonium nitrate fuel oil explosives, the preparation method of explosives with different densities comprises the following steps: (401) uniformly mixing porous granular ammonium nitrate and an emulsion base with negative oxygen balance to obtain a mixture V, wherein the weight ratio of the porous granular ammonium nitrate to the emulsion base is not less than 1:1; and (402) uniformly mixing the mixture V, a sensitizing solution and the physical density adjusting agent and sensitizing at the temperature of 0-90° C. for 15-20 min to prepare the heavy ammonium nitrate fuel oil explosives; wherein the weight ratio of the emulsion base to the sensitizing solution is 100:(1.0-3.2), and the amount of the physical density adjusting agent is 0.1-35% of the total weight of the porous granular ammonium nitrate and the emulsion base.
 28. Explosives with different densities obtained by the preparation method according to claim
 15. 